1. Real World Project: Determination of Vitamin C in Fruit Juices Brian Gillease And Lauren Burns

2. Objective Calculate vitamin C in a Vitamin C tablet Titrate fruit juices Calculate amount of vitamin C in each juice Compare juices to tablet

3. Importance Vitamin C – – antioxidant; binds with carbon, hydrogen, oxygen; oxidizes easily – Safe and efficient nutrient, helps protect body against cardiovascular disease, eye disease, and other diseases

4. Procedures Standardized thiosulfate solution using a starch paste Titrated a vitamin C tablet with thiosulfate to determine the amount of ascorbic acid present Juiced fruits Centrifuged fruits Titrated with thiosulfate

5. Procedures - Errors Juicer – too much pulp Filtration – pulp too thick Strawberry Juice – red color of juice

6. Picture Perfect!

7. Clementine Juice 30 mL filtered, digested soln. + 50 mL KIO3 soln. + KI + 10 mL H2SO4 + starch indicator Trial Mass KI (g) Initial Vol. Na2S2O3 (mL) Final Vol. Na2S2O3 (mL) Vol. Na2S2O3 Added Consumed Moles I3- Moles I3- Present Grams Ascorbic Acid% Difference 12.0013026 0.0011110 92 0.0002935 74 0.0517059 6270.62161244 22.0009028.1 0.0012008 34 0.0002038 32 0.0359000 9179.60222108 32.0022029.5 0.0012606 62 0.0001440 04 0.0253628 4385.5892935 Moles I3- Formed 0.0014046 66 Average 0.0376562 99 78.60437568 Manufacture r's Claim0.176 grams per fruit Data

8. Clementine Juice Spike 30 mL filtered, digested soln. + 50 mL KIO3 soln. + KI + 10 mL H2SO4 + starch indicator Trial Mass KI (g) Mass AA (g) Total Mass AA (g) Initial Vol. Na2S2O3 (mL) Final Vol. Na2S2O 3 (mL) Vol. Na2S2O3 Added Consume d Moles I3- Moles I3- Present Grams Ascorbic Acid % Difference 12.0056 0.003 1 0.020 7022 0.001574 384 - 0.00016 9717 - 0.0298915 87 244.403800 1 22.015 0.003 40.021018.5 0.001323 914 8.07527 E-05 0.0142226 18 32.2732466 8 32.0015 0.004 2 0.021 8020.25 0.001449 149 - 4.44824 E-05 - 0.0078344 84 135.938000 9 Moles I3- Formed 0.0014 04666 Average - 0.0078344 84 137.538349 2 Manufacturer's Claim0.0176

9. Papaya Juice 30 mL filtered, digested soln. + 50 mL KIO3 soln. + KI + 10 mL H2SO4 + starch indicator Trial Mass KI (g) Initial Vol. Na2S2O3 (mL) Final Vol. Na2S2O3 (mL) Vol. Na2S2O3 Added Consumed Moles I3- Moles I3- Present Grams Ascorbic Acid % Difference 12.0009022.2 0.00094870 2 0.00045596 5 0.08030706 2 100.097215 1 22.0022021.4 0.00091451 4 0.00049015 2 0.08632834 793.7988006 32.0014023.2 0.00099143 60.00041323 0.07278045 7 107.970233 2 Moles I3- Formed 0.00140 4666 Average 0.07980528 9 16.5216645 7 Manufacturer's Claim0.0956 grams per fruit

10. Papaya Juice Spike 30 mL filtered, digested soln. + 50 mL KIO3 soln. + KI + 10 mL H2SO4 + starch indicator Trial Mass KI (g) Mass AA (g) Total Mass AA (g) Initial Vol. Na2S2 O3 (mL) Final Vol. Na2S2O3 (mL) Vol. Na2S2O 3 Added Consumed Moles I3- Moles I3- Present Grams Ascorbic Acid % Differenc e 12.00210.00290.0985020 0.0014312 58 - 2.65916E -05 - 0.004683 47 104.7547 914 22.0090.00320.0988018.2 0.0013024 45 0.000102 222 0.018003 836 81.77749 418 32.00290.00360.0992019.3 0.0013811 64 2.35024E -05 0.004139 371 95.82724 659 Moles I3- Formed 0.0014 04666 Average 0.005819 913 94.11984 407 Manufacturer's Claim0.0956

11. Orange Juice 30 mL filtered, digested soln. + 50 mL KIO3 soln. + KI + 10 mL H2SO4 + starch indicator TrialMass KI (g) Initial Vol. Na2S2O3 (mL) Final Vol. Na2S2O3 (mL) Vol. Na2S2O3 Added Consumed Moles I3- Moles I3- Present Grams Ascorbic Acid % Difference 12.005031.1 0.0013290 37 7.56294E- 05 0.0133202 75 73.932925 83 22.0067030.3 0.0012948 49 0.0001098 17 0.0193415 59 62.149590 67 32.0039030 0.0012820 29 0.0001226 37 0.0215995 41 57.730839 99 Moles I3- Formed 0.0014046 66 Average 0.0180871 25 64.604452 17 Manufacturer's Claim0.0511 grams per fruit

12. Orange Juice Spike 30 mL filtered, digested soln. + 50 mL KIO3 soln. + KI + 10 mL H2SO4 + starch indicator Trial Mass KI (g) Mass AA (g) Total Mass AA (g) Initial Vol. Na2S2O 3 (mL) Final Vol. Na2S2O 3 (mL) Vol. Na2S2O 3 Added Consum ed Moles I3- Moles I3- Present Grams Ascorbic Acid % Differenc e 12.01050.0040.0551021 0.00150 2821 - 9.81545 E-05 - 0.01728 7528 131.374 8241 22.00080.00390.055019.35 0.00138 4742 1.99242 E-05 0.00350 9168 93.6196 9371 32.00650.00370.0548018.55 0.00132 7492 7.71746 E-05 0.01359 2415 75.1963 225 Moles I3- Formed 0.0014 04666 Average - 6.19815 E-05 100.063 6134 Manufacturer's Claim0.0511

13. Grapefruit Juice 30 mL filtered, digested soln. + 50 mL KIO3 soln. + KI + 10 mL H2SO4 + starch indicator Trial Mass KI (g) Initial Vol. Na2S2O3 (mL) Final Vol. Na2S2O3 (mL) Vol. Na2S2O3 Added Consumed Moles I3- Moles I3- Present Grams Ascorbic Acid % Difference 12.0022030.1 0.0012863 03 0.0001183 64 0.0208468 8 45.711249 4 21.995033.8 0.0014444 2 -3.97532E- 05 - 0.0070015 6 118.23322 79 32.0039030.5 0.0013033 96 0.0001012 7 0.0178362 38 53.551463 28 Moles I3- Formed 0.00140 4666 Average 0.0105605 2 72.498646 85 Manufacturer's Claim0.0384 grams per fruit

14. Grapefruit Juice Spike 30 mL filtered, digested soln. + 50 mL KIO3 soln. + KI + 10 mL H2SO4 + starch indicator Trial Mass KI (g) Mass AA (g) Total Mass AA (g) Initial Vol. Na2S2O3 (mL) Final Vol. Na2S2O3 (mL) Vol. Na2S2O3 Added Consumed Moles I3- Moles I3- Present Grams Ascorbic Acid % Difference 12.00560.00370.0421019 0.0013596 95 4.49713E- 05 0.0079205 89 81.186249 55 22.0150.00330.0417018.5 0.0013239 14 8.07527E- 05 0.0142226 18 65.893001 92 32.00150.00370.0421019.5 0.0013954 77 9.1898E- 06 0.0016185 6 96.155440 19 Moles I3- Formed 0.00140 4666 Average 0.0079205 89 81.078230 55 Manufacturer's Claim0.0384

15. Strawberry Juice 30 mL filtered, digested soln. + 50 mL KIO3 soln. + KI + 10 mL H2SO4 + starch indicator Trial Mass KI (g) Initial Vol. Na2S2O3 (mL) Final Vol. Na2S2O3 (mL) Vol. Na2S2O3 Added Consumed Moles I3- Moles I3- Present Grams Ascorbic Acid % Difference 12.0012037 0.0015811 69 - 0.0001765 03 - 0.0310866 97 537.84079 67 21.9992028.7 0.0012264 75 0.0001781 92 0.0313841 28 342.02996 76 32.0003025.5 0.0010897 25 0.0003149 42 0.0554692 65 681.25725 02 Moles I3- Formed 0.001404 666 Average 0.0185888 99 161.81547 37 Manufacturer's Claim0.0071 grams per fruit

16. Strawberry Juice Spike 30 mL filtered, digested soln. + 50 mL KIO3 soln. + KI + 10 mL H2SO4 + starch indicator Trial Mass KI (g) Mass AA (g) Total Mass AA (g) Initial Vol. Na2S2 O3 (mL) Final Vol. Na2S2O3 (mL) Vol. Na2S2O3 Added Consume d Moles I3- Moles I3- Present Grams Ascorbic Acid % Differenc e 12.00340.00310.0102018.4 0.001316 757 8.7909E- 05 0.015483 024 51.79435 343 22.00210.00380.0109019.1 0.001366 851 3.7815E- 05 0.006660 183 38.89740 287 32.00180.00350.0106020.2 0.001445 571 - 4.09042E -05 - 0.007204 281 167.9649 177 Moles I3- Formed 0.0014 04666 Average 0.004979 642 86.21889 134 Manufacturer's Claim0.0071

17. Error Source Over titrated thiosulfate Not enough KI – Wasn’t an excess of KI to react with Refrigerate – Juices were not refrigerated Solutions degrade – KIO 3 degraded; did not work

18. Conclusion Papaya juice contained the most Vitamin C; aligned with FDA statistics Numerous errors throughout Overall experiment was unsuccessful; several areas that could be improved